1. Field of the Invention
The present invention relates to a terminal-to-terminal communication connection control system for IP (Internet Protocol) service including IP-service terminal-to-terminal communication connection control system of any or a combination of a terminal-to-terminal communication connection control method for cooperating an IP network (called also an IP transfer network) with another communication network, a terminal-to-terminal connection control method for an IP network applied with the No. 7 common channel signaling system, a terminal-to-terminal connection control method based on an IP-network multicast technique, an apparatus for realizing terminal-to-terminal communication connection control and multicast service or TV conference service. The other communication network includes a public switched telephone network (PSTN) and a mobile communication network used for mobile phones, besides the IP network.
2. Description of the Related Art
The prior arts related to the present invention includes Japanese Patent No. 3084681 C1 (hereinafter, “prior patent”) by the present applicants and Japanese Patent Application No. 078270/2001 (hereinafter, “prior patent application”) by the present applicants.
The prior patent realizes, in an integrated information communication system as an IP packet transfer network adopting an IP encapsulation technique, an IP encapsulation technique, a technique of dynamically setting an address management table by IP-terminal request, and a method of acquiring an IP address by presenting a telephone number to a domain server to register the acquired address in a address management table. Meanwhile, the prior patent application discloses, in a terminal-to-terminal communication connection method using an IP packet transfer network, a simplified encapsulation technique, a method of applying the common channel signaling system onto an IP network, a method of carrying out multicast by registering a user's terminal-unit address into the network node unit, and so on.
Note that the prior patent or patent application uses the terms not the same as the terms used in the present invention. Accordingly, the terms used in the prior patent or patent application will be shown with parentheses in order to avoid confusion. For example, in the case of describing a network node unit (access control apparatus), the access control apparatus is a term used in the prior patent or patent application.
<<IP Encapsulation Technique>>
The IP encapsulation technique disclosed in the prior patent will be outlined with reference to FIG. 1. In this example, an external IP packet 13-1 is transferred from an IP terminal unit 12-1 having an external IP address “EA01” to an IP terminal unit 12-2 having an external IP address “EA02” via an IP network 11-1. A logic communication line 12-3 has an end (logic terminal) to be identified by a logic terminal identifier “Pin1” while a logic communication line 12-4 has an end to be identified by a logic terminal identifier “Pin2”. The logic terminal “Pin1” is given with an internal IP address “IA01”, and the logic terminal “Pin2” is given with an internal IP address “IA02”. The network node unit 11-2, receiving an external IP packet 13-1, confirms that an internal IP address given to the logic terminal “Pin1” inputted by the IP packet 13-1 is “IA01” and a destination IP address of the IP packet 13-1 is “EA02”, to search through the interior of an address management table 11-8. Searched are records including, first, a source internal IP address of “IA01” and, next, a destination external IP address of “EA02”. Furthermore, inspection is made whether the detected record includes a source external IP address “EA01” of within the IP packet 13-1. In the present example, this is a record including “Pin1, IA01, IA02, EA01, EA02” on a second line from above. Using the IP addresses “IA01” and “IA02” of the record, an IP packet 13-2 is formed (IP packet encapsulation).
The internal IP packet 13-2 passes through routers 11-4, 11-5, 11-6 to reach a network node unit 11-3. The network node unit 11-2 removes the received internal IP packet 13-2 of an IP header (IP packet decapsulation) and forwards an obtained external IP packet 13-3 onto a communication line 12-4. An IP terminal unit 12-3 receives the external IP packet 13-3. The fist-lined record “Pin1, IA01, IA81, EA01, EA81” of an address management table 11-8 is used to encapsulate an external IP packet directed toward a server 11-7 having an external IP address “EA81” and an internal IP address “IA81”. By changing a destination external IP address of an external IP packet inputted at the same logic terminal (terminal end of a logic communication line 12-3) to “EA01”, “EA81” or so, the destination where the external IP packet is to reach can be changed. Note that the mask technique in IP encapsulation is known, e.g. explained in FIG. 362 of the prior patent application.
<<Simplified Encapsulation Technique>>
With reference to FIG. 2, outlined is a simplified encapsulation technique disclosed in the prior patent application. The internal packet formed by simplified encapsulation is different from the foregoing IP encapsulation in that containing a destination internal address but not containing a source internal address. A logic communication line 22-3 at its end (logic terminal) is determined by a logic terminal identifier “Pin1” while a logic communication line 22-4 at its end (logic terminal) is determined by a logic terminal identifier “Pin2”. An internal IP address “IA01” is provided to the logic terminal “Pin1”, and an internal IP address “IA02” is provided to the logic terminal “Pin2”. In the present example, an external IP packet 23-1 is transferred from an IP terminal unit 22-1 having an external IP address “EA01” to an IP terminal unit 22-2 having an external IP address “EA02”. The network node unit 21-2, upon receiving an external IP packet 23-1, confirms that an internal IP address given to the logic terminal “Pin1” inputted by the IP packet 23-1 is “IA01” and a destination external IP address of the IP packet 23-1 is “EA02”, to search an address management table 21-8. Searched are records including, first, a source internal IP address of “IA01” and, next, a destination external IP address of “EA02”. Furthermore, inspection is made whether the detected record includes a source external IP address “EA01” of within the IP packet 23-1. In the present example, fallen under is a record including “Pin1, IA01, IA02, EA01, EA02” on a second line from above. The IP addresses “IA01” and “IA02” in the record are used to form an IP packet 13-2 having a simplified header whose destination IP address is “IA02” (simplified encapsulation). The internal IP packet 23-2 reaches a network node unit 21-3 by way of routers 21-4, 21-5, 21-6. The network node unit 21-2 removes the received internal IP packet 23-2 of its simplified header (simplified decapsulation) and forwards an obtained external IP packet 23-3 onto a communication line 22-4. The internal packet is to be realized by an optical frame having communication two layers including, for example, only a destination address. Such an optical frame includes a MAPOS being known, for example.
Incidentally, the IP encapsulation and the simplified IP encapsulation, in any, can use as a logic terminal identifier a logical terminal identification number at an end of a communication two-layered address (physical address, MAC address or the like), for example. Meanwhile, similarly to the IP encapsulation technique, a destination where an external packet is to reach can be changed by changing a destination external IP address of within the external IP packet inputted at the same logic terminal.
<<Technique for Dynamically Setting Address Management Table upon Request of IP Terminal Unit>>
The prior patent discloses, in Embodiment 35, a method to change a setting content of an address management table (conversion table) of within a network node unit (access control apparatus) from a user's IP terminal. This will be explained with reference to FIG. 3.
An IP terminal unit 23-1 sends an external IP packet (ICS user frame) containing a domain name “c5. b2. a1” to a conversion table server 23-2 (Step 23-4). The conversion table server 23-2 makes an inquiry to the domain name server 23-3 (Step 23-5). The domain name server 23-3 searches for and acquires an internal address (ICS network address) and external IP address (ICS user address) corresponding to the domain name “c5. b2. a1” (Step 23-6). Then, this is sent back to the conversion table server 23-2 (Step 23-7). The conversion table server 23-2 writes it into a conversion table (Step 23-8), for report to the IP terminal 23-1 (Step 23-9).
<<Method for Acquiring IP Address by Telephone Number as Domain Name>>
Next, Embodiment 36 of the prior patent discloses that IP packets (ICS user frames) can be communicated with the other end of communication by using a telephone number as a domain name wherein the IP packet stores therein a digitalized voice thereby enabling public communication by the telephone. An address management server (conversion table server) converts an input domain name into an external IP address (ICS user address) to send it back, and registers an internal address (ICS network address) in an address management table (conversion table) of the network node unit (access control apparatus).
A telephone number “1234-5678” inputted to a telephone set is delivered to a conversion table server via a telephone number input section of the telephone set. The conversion table server 24-4 (FIG. 4) makes an inquiry to a plurality of domain name servers 24-1, 24-2, 24-3 one after another (24-6 to 24-11 in FIG. 4) on the basis of the received telephone number “1234-5678”, and acquires an internal address and external IP address of a telephone set at the other end of communication upon considering the telephone number “1234-5678” as a domain name. Next, the conversion table server 24-4 prepares a new item to be added to the address management table (conversion table) of within the network node unit by using acquired two addresses, and sends it to a requesting telephone set. Also, the network node unit uses the new item of the address management table as a new element of the address management table in the network node unit.
<<Method for Applying the No. 7 Common Channel Signaling System to IP Network>>
This is a technique disclosed in the prior patent application. As shown in FIG. 5, connection servers 25-5 to 25-6 and a relay connection server 25-7 are provided in an IP network 25, to connect terminal units 25-1 and 25-2 to the connection server via a media router 25-3 or 25-4. Note that the connection server and the relay connection server are referred also to as telephone management servers. The connection servers 25-5 and 25-6 are provided with a function similar to the line-connection control of a line switch (LS) in a public switched telephone network (PSTN) while the relay connection server 25-7 is with a function similar to the line-connection control of a tall switch (TS). Terminal units, such as telephone sets, IP terminal units or video terminal units, send and receive an initial address message (IAM) capable of making equally corresponding to the line-connection control message of the common channel signing system, an address complete message (ACM), a call progress message (CPG), an answer message (ANM), a release message (REL) and a release completion message (RLC) by way of an interior of the IP network, thereby realizing a terminal-to-terminal communication connection control method using an IP network. Note that a terminal-to-terminal communication connection control method is feasible between the two connection servers 25-5 and 25-6 wherein a relay connection server 25-7 does not exist.
The utilizer inputs a destination telephone number on the terminal unit 25-1 (Step Z1). The media router 25-3 sends back a call set acceptance (Step Z2). The media router 25-3 sends an IP packet including a destination telephone number and source telephone number to set a call (Step Y1). An IAM packet forwarded from the connection server 25-5 passes the connection server 25-6 (Steps Y2, Y3) to reach the media router 25-4 (Step Y4). The media router 25-4 requests the terminal unit 25-2 to set a call (Step Z4). The connection server 25-6 sends back an ACM packet (Steps Y5, Y6). The terminal unit 25-2 reports of an incoming call tone (Step Z7). The media router 25-4 sends an incoming call to the connection server 25-6 (Step Y7). The connection server 25-6 sends a CPG packet (Steps Y8, Y9) to notify a ring-back tone to the terminal unit 25-1 via the media router 25-3 (Step Y10, Step Z10). The terminal unit 25-2, responding to the call set request, makes a notification to the connection server 25-6 (Step Z11, Step Y11). The connection server 25-6 forms and sends an ANM packet. The terminal unit 25-1 enters into a voice communication phase (Steps Y12 to Y14, Step Z14).
When the utilizer ends the voice communication on the terminal unit 25-1, a disconnect request on the terminal unit 25-1 is notified (Step Z16). A REL packet signifying a series of release requests and a RLC packet meaning a completion of release request are communicated, thereby closing the call connection (Steps Y16 to Y23, Steps Z22 and Z23). The step of between the connection server 25-2 and the connection server 25-6 (Y2, Y3, etc.) is referred to as an NNI, while the step of between the connection server and the media router (Y1, Y3, etc.) is referred to as a UNI.
<<Detailed Example of Between IP Network Applied with Common Channel Signaling System and Public Switched Telephone Network>>
The Embodiments 13 to 16 of the prior patent application, adopting a concept of the common channel signaling system, have a feature of separating the interior of an IP network with a control communication line and a voice communication line. This discloses a method of controlling the communication connection between telephone sets through the IP network and public switched telephone network. In FIG. 6, numeral 40-1 is an IP network, numeral 40-2 is a public switched telephone network, numeral 40-3 is a gateway having an encapsulation function, numeral 40-4 is a relay gateway, numeral 40-5 is an IP communication line, numeral 40-6 is a control communication line on the common channel signaling system, and numeral 40-7 is a voice communication line. Numeral 40-8 is a control IP communication line and numeral 40-9 is a voice IP communication line. Numerals 41-1 and 41-2 are telephone sets, numeral 41-3 is a media router, numeral 42-1 is a tall switch, numeral 42-2 is a subscriber exchange, numeral 42-3 is a relay control section (STP), numeral 42-4 is a voice control section having an encapsulation function, and numeral 42-5 is a terminal-unit control section (SEP). Numeral 43-1 is a proxy telephone server, numeral 43-2 is a telephone management server, numeral 43-3 is a telephone number server, numerals 43-4 and 43-5 are table management servers, numerals 44-1 and 44-2 are network node units having encapsulation and decapsulation functions, numerals 44-3, 44-4, 44-5, 44-6 are respectively routers. The relay control section 42-3 is given with an IP address. The relay control section 42-3 is a signal transfer point (STP) on the common channel signaling system. as viewed from the public switched telephone network 40-2, and given with a signaling point address.
The terminal-unit control section 42-5 of FIG. 6 corresponds to the connection server 25-5 of FIG. 5, and the relay control section 42-3 of FIG. 6 corresponds to the relay connection server 25-7 of FIG. 5. Herein, “correspondence” means that the terminal unit control section 42-5 and the relay control section 42-3 have a function to effect line-connection control based on the common channel signaling system.
In case the telephone set 41-1 requests a call set to the telephone set 41-2, an initial address message (IAM), an address completion message (ACM), a call progress message (CPG), an answer message (ANM), a release message (REL), a release completion message (RLC) and the like are communicated by way of the media router 41-3, network node unit 44-1, terminal-unit control section 42-5, routers 44-4 to 44-5, relay control section 42-3, control communication line 40-6, exchange 42-1 and exchange 42-2, thereby effecting a terminal-to-terminal communication connection control using the IP network. Herein, the voice forwarded from the telephone set 41-1 reaches the telephone set 41-2 by way of the media router 41-3, network node unit 44-1, router 44-6, network node unit 44-2, voice IP communication line having a function of voice control section encapsulation 40-9, exchange 42-1 and exchange 42-2.
The relay control section 42-3 defines the various parameters to be defined by the common signaling system, e.g. circuit identification code (CIC) and signaling link selection (SLS), according to a rule previously arranged with the public switched telephone network 40-2. The relay control section 42-3 writes a signaling point address, signaling link selection and circuit identification code of the relay control section 42-3, together with a media path identifier, to an address connection table 45-1. The relay control section 42-3, managing a gateway address management table 45-2, can search through the gateway address management table 45-2 to acquire an IP address of a gateway managing a destination telephone number, i.e. an IP of a gateway for connection to a telephone set having a destination telephone number. The relay control section 42-3, managing a signaling point address management table 45-3, can search through the signaling point address management table to acquire a signaling point address of an exchange of within the public switched telephone network 40-2. The relay control section 42-3 makes a notification to the encapsulation-functioned voice control section 42-4 via an information line 45-4. The encapsulation-functioned voice control section 42-4 writes the notified information as a record of the media path connection table 45-4 and makes notification of a write completion. The media path identifier is used to identify a voice communication path used for a telephone call (connection/voice communication/release) of between telephone sets. Incidentally, the encapsulation-functioned voice control section 42-4 is configured to define a logic communication line for transmit a voice from the encapsulation-functioned voice control section 42-4 onto the voice communication line 40-7 and write the logic communication line identifier as a record of the media path connection table 45-4.
The encapsulation-functioned voice control section 42-4 converts a voice stored in an IP packet forwarded from the voice IP communication line 40-9 into a form for transfer within the public switched telephone network 40-2, and sends it onto the voice communication line 40-7. Also, the encapsulation-functioned voice control section 42-4 converts a voice frame forwarded from the voice communication line 40-7 of the public switched telephone network 40-2 into an IP packet form, and sends it onto the voice IP communication line 40-9. The voice control section has therein an IP address to send and receive a voice IP packet, thus serving for a setting of the media path connection table 45-4.
The prior patent application discloses a technique for transferring a message (IAM, ACM, . . . , REL, etc.) for telephone line-connection control by storing it in an IP packet (FIG. 142, etc. of tenth embodiment). The line control conforming to the common line signaling system is applied to a level above the three layers of a communication layer (network layer).
The line-connection control messages (IAM, ACM, CPG, ANM, REL, RLC) conforming to the common channel signaling system are to be set in a payload section of an internal IP packet. Explanation will be made using a protocol stack 59-1, 59-2 (FIG. 7). In designating a protocol type as an item in a header of an internal IP packet, there is a method of defining “CC” (connection control) representative of line-connection control as a new prototype to store the line-connection control messages in a payload section of the internal IP packet. As another method, there is a method of designating the protocol type as “ICMP” to store the line-connection control messages in an ICMP message area in the internal IP packet.
As a still another method, there is a method of designating the protocol type as “UDP” to store the line-connection control messages in a payload section in a UDP segment of an internal IP packet. The method with a protocol stack 59-1 is a method of providing a data link layer on a physical layer as the lowermost layer, an IP layer thereon (network layer), and a new line-connection control layer (CC layer) in a level that. The method with a protocol stack 59-2 is a method of providing a UDP layer or ICMP layer in a level above an IP layer, and a line-connection control layer (CC layer) thereon.
The fourteenth embodiment of the prior patent application explains, as shown in FIG. 8 (part of FIG. 232 of the prior patent application), a terminal-to-terminal communication connection control method to carry out a telephone communication from a telephone set 1420 to a telephone set 1421 by way of a public switched telephone network 1405, an IP network 1400 and a public switched telephone network 1406. Outlining will be made on a scope concerned with the invention.
When taking a receiver of the telephone set 1420, a signal unit 1451 based on the common channel signaling system is transferred to the relay control section 1423 of within a relay gateway 1401 via a control communication line 1415. The signal unit 1451 has a destination point code of “DPC-1”, a source point code of “OPC-1”, a signaling link selection of “SLS-1”, a circuit identification code of “CIC-1”, a message of “IAM” and a parameter of “Para-1”. The parameter “Para-1” has a content including a telephone number “TN-1” of the telephone set 1420 and a telephone number “TN-2” of the telephone set 1421. The relay control section 1423 receives the signal unit 1451 and forms an IP packet 1451. The IP packet 1452 has a destination IP address of “D-ad-x”, a source IP address of “S-ad-x” and a circuit identification code of “CIC-x”, and includes a telephone number “TN-1” of the telephone set 1420 and a telephone number “TN-2” of the telephone set 1421. The relay control section 1423 sends the IP packet 1452 formed in the above into the IP network 1400. The IP packet 1452 reaches the relay control section 1424 of within the relay gateway 1402, which, in the relay control section 1424, is converted into a signal unit 1453 to reach the telephone set 1421 via the public switched telephone network 1406. The relay control section 1423 and the voice control section 1427 exchange information, such as port numbers, through the information line 1429-1.
FIG. 9 shows a function of the relay control section 1423 within the relay gateway 1401 by separating the communication function layer. The signal unit 1451 forwarded from the control communication line 1415 is connected to an MTP as a communication function layer on the common channel signaling system. The communication function layer 1423-1 deals with the communication processing concerning a destination point code DPC-1, source point code OPC-1 and signaling link selection SLS-1 of in the signal unit 1451. The communication function layer 1423-2 deals with the communication processing concerning a message IAM, circuit identification code CIC-1 and parameter Para-1 of in the signal unit 1451. On the other hand, the communication function layer 1423-3 deals with the communication processing concerning a destination IP address D-adx and source IP address S-adx contained in the IP packet 1452. The communication function layer 1423-4 deals with the communication processing concerning a message IAM and circuit identification code CIC-x of in the IP packet 1452.
As in the above, the gist lies in that the communication function layers 1423-2 and 1423-4 carry out a mutual conversion of between the packet 1451 on the common channel signaling system and a packet 1452 conforming to a rule in the prior patent application.
<<Outline of Multicast>>
Next, explanation is made on a multicast-type IP network 27-1 for a transfer of from one source of delivery to a plurality of destinations, with reference to FIG. 10.
Routers 27-11 to 27-20 respectively hold multicast tables. An IP packet 29-1 having a multicast address “MA1” is sent from an IP terminal unit 28-1 to reach the router 27-18 via the router 27-11. By making reference to a router-dependent multicast table held in the router 27-18, an IP packet 29-3 and IP packet 29-4 are transferred onto a communication line. The IP packet 29-3 is copied in the router 27-17 and turned into IP packets 29-5 and 29-6, while the IP packet 29-5 is copied in the router 27-12 and turned into IP packets 29-8 and 29-9, respective of which reach an IP terminal unit 28-2 and an IP terminal unit 28-3. The IP packet 29-6 is copied in the router 27-13 and turned into an IP packet 29-10 and 29-11, respective of which reach IP terminal units 28-4 and 28-5. The IP packet 29-4 passes the routers 27-19, 27-14, and copied IP packets 29-12 and 29-13 respectively reach IP terminal units 28-6 and 28-7.
Incidentally, known is the method of transferring multicast data by storing it in a UPD segment of in an IP packet, which is applicable to the foregoing multicast. The routers 27-11 to 27-14 shown in FIG. 10 are network node units. In the technique disclosed in Embodiment 18 of the prior patent application, an address of a terminal unit is previously registered in an address management table of a network node unit so that, by the means for examining an address included in communicated multicast data, realized is a multicast IP-packet communication capable of preventing against not-allowed transmission of multicast data thereby enhancing information security and imposing multicast data fee onto the recipient.
<<Example of Multicast Communication>>
This is an example disclosed as Embodiment 20 in the prior patent application. Explanation will be made with reference to FIG. 11. Within an IP network 31-1, there are provided a range 31-2 under the management of communication company X and a range 31-3 under the management of communication company Y, network node units 32-1 to 32-12, routers 34-1 to 34-11, and a router 34-12. The network node units and the routers are connected directly by IP communication lines or indirectly through the network node units and routers. The terminal units 33-1 to 33-17 having an IP packet transmitting/receiving function are connected to the network node units via IP communication lines. Numerals 33-24 to 33-27 are multicast P service proxy servers, numerals 33-28 to 33-31 are multicast Q service proxy servers, and numerals 33-32 to 33-35 are overflow communication line servers. The communication companies X and Y jointly manage the routers 34-12. A multicast system with IP encapsulation is disclosed in the Embodiment 17 in the proceeding patent.
<<Transmission Terminal Units and Transmission Management Servers of Communication Company>>
The electronic newspaper distribution service by a newspaper company A is classified as multicast P service and the news distribution service by a broadcasting station B is as multicast Q service. The terminal unit 33-1 is a multicast data transmitting terminal unit under the management of the communication company X, the terminal unit 33-2 is a transmission management server under the management of the communication company X, a terminal unit 33-4 is a multicast data transmitting terminal unit under the management of the communication company Y, a terminal unit 33-6 is a transmission management server under the management of the communication company Y, and a terminal unit 33-7 is a terminal unit under the management of the newspaper company A which is a terminal unit for multicast P service to transmit an electronic newspaper prepared by the newspaper company A to the transmission management server 33-2 of the communication company X and to the transmission management server 33-6 of the communication company Y thus effecting the administrative correspondence communication concerning electronic newspaper distribution. A terminal unit 33-3 is a terminal unit under the management of the broadcasting station B, which is a terminal unit for multicast Q service to transmit the (voice-moving image) TV news distribution service offered by the broadcasting station B to the transmission management server 33-2 of the communication company X and to the transmission management server 33-6 of the communication company Y thus effecting the administrative correspondence communication concerning electronic newspaper distribution. The transmission management server 33-2 carries out an administration procedure concerning multicast data transmission, such as distributing an electronic newspaper prepared by the newspaper company A on behalf of the communication company X, TV news distribution service by the broadcasting station B and electronic stock-price guide service by a stock company C. Similarly, the transmission management server 33-6 carries out an administration procedure concerning multicast data transmission on behalf of the communication company Y.
<<Data Distribution via Multicast Service Proxy Server>>
Furthermore, the prior patent discloses a multicast technique having an intervening multicast service proxy server, which will be explained in the below (see FIG. 325 of the prior patent). Disclosed is a technique that the multicast data forwarded from the transmission terminal and transferred into the IP transfer network, reaches a multicast service proxy server set up on a reception side, the multicast service proxy server receiving the multicast data, the multicast service proxy server then transmitting the multicast data toward a plurality of terminal units connected to a network node unit by the use of a multicast data distribution function of within the network node unit, the terminal units in plurality receiving the multicast data.
<<Mobile Terminal Unit>>
The prior patent application discloses a technique of communication from a mobile terminal unit through a radio communication path. This will be outlined with reference to FIG. 12. Text data is forwarded from an IP terminal unit 128-1 to reach a radio transmitting/receiving section 123 of within an IP transfer network 120 by way of a radio interface converting section 129-1, a radio transmitting/receiving section 127 and a radio communication path 125, and to reach a network node unit 121 via a gateway 122, being transferred within the IP transfer network 120 to reach another terminal unit via another network node unit. The digital voice forwarded from an IP telephone set 128-2, similarly, reaches another telephone set via the IP transfer network. An IP voice image unit 128-3 also is similar to the above, and voice and image data reach another IP voice image unit via the IP transfer network.
<<Telephone Communication via Media Router>>
The prior patent application discloses a technique of telephone communication via a media router, which will be explained with reference to FIGS. 13 and 14. In this example, a media router 1021 has an IP address “EA1” and a media router 1022 has an IP address “EA2”. Digital voice is stored in an IP packet given with a local IP address and forwarded from a telephone set 1011 to reach the media router 1021. Next, the media router 1021 turns into an external IP packet having a source address “EA1” and destination address “EA2”. The external IP packet reaches a network node unit 1031 via a communication line 1040. This turns into an internal packet by the use of a first-lined record of an address management table 1034. The internal packet is transferred within the IP network to reach a network node unit 1032. The internal packet is decapsulated and the external IP packet is restored. This passes a communication line 1041 to reach a media router 1022 where it is stored in an IP packet given with a local IP address, thus reaching a telephone set 1012.
Next, with reference to FIG. 15, shown is another disclosure example of another media router 1021-1. This is an example that a connection control section 1080-1 has an external address “EA1”. The voice, forwarded from a telephone set 1011-1 having a telephone number “Tel-No-1”, passes a pin number “T1” at an end of a communication line to reach a telephone control section 1081-1. The connection control section 1080-1 makes reference to a first-lined record “Tel-No-1, T1, 5004” of a telephone number/pin number/UDP port number correspondence table 1083 in an inside thereof to adopt a port number “5004”, and forms an external packet storing a voice having a source address “EA1” and a port number “5004” of a UDP or TCP packet within an IP packet. Namely, the media router 1021-1 is characterized by a technique that an external address “EA1” and port number “5004” is assigned to a telephone set having a telephone number “Tel-No-1”.
Next, with reference to FIG. 16, shown is another disclosure example of another media router 1021-2. The media router 1021-2 includes a telephone control section 1081-2, a PBX control section 1085-1, a connection control section 1080-2, routers 1086, 1087. An IP packet, forwarded from a terminal unit 1090 of within a LAN 1093, reaches a network node unit of within the IP network by way of a router 1087, a communication line 1089, a router 1086 and a communication line 1040-2. Similarly, an IP packet containing the same image data, forwarded from a moving-image transceiver 1092, reaches a network node unit of within the IP transfer network by way of a router 1087, a communication line 1089, a router 1086 and a communication line 1040-2. It is possible to transfer an IP packet in a reverse direction.
In order for implementing IP full service using an IP network, there is no terminal-to-terminal communication connection control method for a common carrier to provide IP full service, i.e., (1) terminal-to-terminal communication connection control method using a mobile communication network and IP network, (2) method for implementing line-connection control in a level above a TCP layer, using telephone numbers, (3) method for implementing TV conference communication using IP-network multicast function, (4) method of configuring a relay gateway unit for connecting an IP network and a PSTN, (5) method of setting an entire or part of an external address in an internal-packet address area, (6) method of setting an entire or part of an external address in an internal frame, (7) method of implementing various functions of network node units within an IP network, (8) method of carrying out fixed telephone, mobile phone and multimedia communications on the same IP network, (9) method of implementing security ASP, (10) method of transmitting and receiving multicast data without distinction between mobile and fixed terminal units, (11) method of switching a radio base point during voice communication, and so on.